Kano - Six men in green uniform stand in the back of a pick-up truck in northern Nigeria's biggest city, on the look-out for prostitutes, their clients, transvestites, drunks and drug addicts.
Their patrols in Kano also scout for men and women deemed to be dressed indecently, examples of supposedly "immoral" behaviour and even Western-style haircuts they consider violations of Islamic law, known as sharia.
"Once we receive an intelligence report or a tip-off of an immoral act being committed in a particular place, we mobilise our men to the area and put an end to it and arrest the perpetrators for either counselling or prosecution," Adamu Haruna Bayero, who heads the patrol, told AFP.
In recent weeks, the sharia enforcers, or Hisbah, have launched sweeping crackdowns and made hundreds of arrests in Kano following a state-government directive to cleanse the commercial hub of so-called immoral practices.
Often their raids coincide with religious festivals, when the boundaries of what is considered decent are pushed to the limit, particularly among the city's youth.
But others suspect a political motive after rivals of the governor, Rabiu Musa Kwankwaso, accused him of lacklustre support for sharia, which is in place across northern Nigeria and coexists with secular, state law.'Balotelli haircuts'
The 9,000-strong moral police force in Kano was formed in 2001 but has since assumed other duties, such as community development work and alternative dispute resolution.
Since its creation, its supporters say it has become an essential part of daily life, tackling issues such as high levels of drug addiction and prostitution, problems that have festered amid unemployment rates that are the worst in the country.
"Some areas you can go and see people romancing on the road," said Haruna as he patrolled the city, occasionally making phone calls to Hisbah intelligence operatives giving him the location of the next raid.
In Kano's market, many support the Hisbah's actions.
"Our youth wear tight trousers and they pull them down from their waist," one man said.
"They also have a type of haircut like footballer (Mario) Balotelli or the (Zinedine) Zidane cut. There are so many of them."
At night, the Hisbah shines its torches into brothels and motorised rickshaws -- a key means of transport in the city -- to determine whether young men and women are using them for canoodling and cavorting.
The group's raids have extended to red-light districts in the mainly Christian Sabon Gari part of the city, prompting claims of persecution by the minority community.
Religion is a volatile subject in Nigeria, which is roughly divided into a mainly Muslim north and largely Christian south, and where extremist group Boko Haram is waging a deadly insurgency to carve out a hardline Islamic state.
But the Hisbah insists that its policing targets all faiths.
"Those arrested include Muslims and non-Muslims and we treat them equally because this is about morality," said Hisbah spokesman Mohammed Yusuf Yola.
The group's deputy commander general, Nabahani Usman, said those arrested for a first and second offence are typically counselled. Repeat offenders are taken to court, leading to a fine or even a jail term.
The group's actions may seem extreme but the Hisbah says the sanctions provided in law are not enough of a deterrent.
Offenders from a recent raid were given the option of a two-month jail term or fine ranging from 10,000 naira to 15,000 naira ($63 to $95). Most paid the fines to escape prison.'Lesbians in our Internet'
For Usman, a lack of parental control and family values due to high divorce rates and poverty in the city are to blame for the rising tide of what he considers immoral behaviour.
Some 400 factories in Kano have shut over the past two decades, damaging Kano's economy and leaving many families impoverished. With parents unable to educate their children properly, many turn to crime and drugs, he said.
Foreign culture is also creeping in from satellite television and the Internet, he added.
"We have recently discovered that there is a lesbian group -- Kano lesbian group -- in our Internet, which is a very unfortunate situation," he said.
Usman accepts that the Hisbah has limited powers and capacity to police the Internet or the airwaves. As a result, he said, the group is attempting to enforce compliance with sharia by preaching to preserve Kano's culture and traditions.
"That is why we in the Hisbah mobilise our men to every nook and corner, just to preach to them that unless our society is cleansed of all these kinds of things we will not know where we will find ourselves in the near future," he said.